Hi I purchased bitcoins for a few days ago and today I see that they are missing in my Bitcoin core wallet.
What has happened? And how do I get them back?
So many possibilities...
Lets start by getting a better understanding of what actually might have happened.
Where did you purchase the bitcoins?
Were you holding the bitcoins at the website/service where you purchased them, or did you send them to your own wallet?
If you sent them to your own wallet:
What wallet software are you using?
Did you initially see the bitcoins arrive at that wallet, or have they never shown up there?
Do you know what bitcoin address you used to receive them at that wallet?
Have you looked on a block explorer to see if they have a record of bitcoins being sent to that address?
If you were holding the bitcoins at the website/service where you purchased them:
Have you contacted support for that website/service to see if they are experiencing temporary technical difficulties?
Do you have more than one login account at that website/service, and if so are you sure you are logged in to the correct account?
Is there any chance that you accidentally clicked on a phishing link that was designed to look like the website/service that you intended to use, but which was actually a fake copy?
Do you know anybody else that uses that service/website? If so, have you checked with them to see if they are having a similar problem?